Impact of greenhouse warming on mesoscale eddy characteristics in high-resolution climate simulations

Abstract

Mesoscale eddies are prevalent throughout the global ocean and have significant implications for the exchange of heat, salt, volume, and biogeochemical properties. These small-scale features can potentially influence regional and global climate systems. However, the effects of climate change on ocean eddies remain uncertain due to limited long-term observational data. To bridge this knowledge gap, this study focuses on examining the impact of greenhouse warming on surface mesoscale eddy characteristics, utilizing high-resolution climate simulation project. Our model experiments have provided valuable insights into the potential effects of greenhouse warming on mesoscale eddies. They suggest that under greenhouse warming conditions, mesoscale eddies are likely to become more frequent and exhibit larger amplitudes and radii, especially in regions characterized by strong ocean currents such as the Antarctic Circumpolar Current and Western Boundary Currents. However, an intriguing pattern emerged in the Gulf Stream, where increased eddy occurrence and radius coincided with a significant decrease in amplitude. This phenomenon can be attributed to the influence of eddy lifespans, as the increased occurrence of long-lived eddies in the Kuroshio Current led to amplified amplitudes, whereas the decreased occurrence of long-lived eddies in the Gulf Stream resulted in a significant decrease in amplitude. The distinction arises from the capacity of eddies with longer lifespans to accumulate more energy compared to their shorter-lived counterparts. These findings provide valuable insights into the complex dynamics of mesoscale eddies in a warming world.